Apparatus for producing glare screens



May 26, 1953 6 Sheets-Sheet 1 hummer 5 4;- 09 m and jl V IQaaK 'wzo M 226556 jwcv/le Gilarnegs J. D. RYAN ETAL 2,639,687

y 6,1953 J. D. RYAN EHL 2,639,687

APPARATUS FOR PRODUCING GLARE SCREENS Filed Dec. 4, 1951 e Sheets-Sheet 2 zzafiegi-Jame (Immune;

May' 26, 1953 J. 0. RYAN EI'AL 2,539,587

APPARATUS FOR PRODUCING GLARE SCREENS Filed Dec. 4, 1951 6 Sheets-Sheet 3 5 4?. 6 (Mommy;

May 26, 1953 J. DQRYAN ETAL 2,639,687

APPARATUS FOR PRODUCING GLARE SCREENS Filed Dec. 4, 1951 s Sheets-Sheet 4 96 1za I I o o j I ZSnventora 90:! /z 49. mu! 7%?! f 77 252 attorneys J. D. RYAN' ETAL APPARATUS FOR PRODUCING GLARE SCREENS May 26, .1953

6 Sheets-Sheet 6 Filed D60. 4, 1951 s s 4 a z 1 o DISTANCE FnoMToPOF Wmosmswln'lucnes 04 a m )Qaa 06 $0556 Muvfle w Patented May 26, 1953 APPARATUS FOR PRODUCING GLARE SCREENS Joseph D. Ryan and Paul T. Mattimoe, Toledo, Ohio, assignors to Libbey-Owcns-Ford Glass Company, Toledo, Ohio, a corporation of Ohio Application December 4, 1951, Serial No. 259,774

4 Claims. 1

The present invention relates generally to glare screens, and more particularly to a novel type of laminated safety glass window, windshield or the like that is provided with a built-in glarereducing portion.

This application is a continuation in part of our copending application, Serial No. 153,782, filed April 4, 1950, which is a division of our application, Serial No. 60,725, filed November 18, 1948. Application Serial No. 153,782 is now Patent No. 2,609,269, dated September 2, 1952.

Briefly stated, this invention contemplates a laminated safety glass unit which includes a nonbrittle plastic interlayer having a colored or neutral shaded glare-reducing portion which is preferably of a shade graduated from deep or opaque at one side of its area to practical extinction at another, laminated with one or more sheets of glass which have a relatively high luminous transmittance in the visible region of the spectrum, but have relatively low ultra-violet light transmittance.

The article of the invention has particular utility when employed as a window or windshield in vehicles, or in other places where the elimination or reduction of glare from the sun or objectionably bright artificial light is desirable. The importance of reducing glare through the window and Windshields of passenger automobiles, buses, railroad trains, and aircraft of all kinds has, of course, long been recognized, and a great deal of work has been done in attempting to provide adequate and satisfactory glare-reducing means for this purpose.

Probably, the greatest proportion of this work has been concentrated on the reduction of glare through the Windshields of automobiles, first, because clear vision through the windshield is of utmost importance and, second, because it is from the windshield that both driver and passengers are most likely to be inconvenienced and made uncomfortable by glare, not only from direct and reflected rays of the sun, but also from the headlights of oncoming vehicles, and so forth.

Moreover, the trend in present day automotive design is toward ever increasing window areas in automobiles and, in the case of Windshields in particular, the tendency is not only to make them wider, but higher as well, and to carry them farther and farther into what was formerly considered to be the roof area of the car. Such modern, streamlined, and rather revolutionary designing presents new and much more diflicult problems from the standpoint of glare, and renders known glare-reducing means virtually obsolete and of minimum practical value. For example, the familiar cloth visors now widely used in automobiles are not practicable for the new type Windshields. Moreover, such visors are unsatisfactory because of their complete opacity and the fact that they cut off a large share of the drivers vision when in operative position and make it impossible for him to see stop lights without peering around or under the visor.

Now, it is an aim of the present invention to provide a special type of laminated safety glass unit, having an integral glare-reducing portion of a special type, for use as a window or windshield, and which lends itself readily to even the most extreme, modern, automotive designs.

Another object is the provision of a unit of the above character in which at least a portion of the plastic interlayer is colored, or neutrally shaded, to provided a glare-reducing or glareeliminating area, that is free from haze, in the unit.

Another object is to provide, in such a unit, a glare-reducing portion which is vignetted; that is, in which the color or neutral shade is very deep or intense in the area presenting the greatest glare, but tapers off gradually to a very low intensity, or to no shade or color at all, as it approaches the essential sighting area of the unit.

The importance of this accomplishment cannot be over-emphasized since experience has shown that an internal visor of uniform shade with sharp cut-oiT between low and high light transmitting areas is most distracting to the operator of a vehicle. Not only does fatigue result because of the rapid rate of eye accommodation required in shifting of the eye from a low level of illumination to a high level, but distraction results from the rapid rate of shift of the sharp cut-01f as the vehicle, and particularly an automobile, responds to unevenness of the highway. Another extremely bothersome factor arising from a sharp cut-off is the failure to properly provide for height differences of individuals operating a vehicle. Thus, a visor appropriate for a shorter individual is totally unsuited for a taller one, since his eye level line is too high, requiring ducking of the head for easy operation.

Another object is the provision of a light stable, antiglare window orwindshield of this same general character in which the glare-eliminating or "reducing portion of the unit is produced by dyeunit of a glass sheet or sheets of a character which absorb or otherwise reduce the transmission of objectionable light rays into and through the unit, and which have antiglare properties of their own.

Other objects and advantages of the invention will become more apparent during-the course of the following description, when taken in connection with the accompanying drawings.

In theiqdrawings, wherein like numerals areemployed to designate like parts throughout the same: r

Fig. l is a fragmentaryperspective view of an automobile having a windshield producedin ac-- Fig. 6 is-a vertical-transverse sectiontaken on the line in Fig. 3; showingthe first rinsing section of the dyeingapparatus;

Fig. 7 is a, erspectiveview of'some of the spraying elements-gfor rinsingthe plastic sheets;

Fig. 8 is a perspective view of a dipping frame showing a shet ofplastic. attached along its perimeter;

Fig. 9 is apartial longitudinalsectionof the dyeing apparatus and, more particularly, of the first and second rinsing, sections;

Fig. 10 is an-end view of the dyeing apparatus, the rinsing head being shown raised, as at' entry of plastic sheets;

Fig. 11 is a fragmentary side view ofthe end of the apparatus, therinsing headbeingv positioned at the lower extremity of its movement. Also illustrated therein is the .lockingdevice, for retaining said headin-a position substantially as shown in Fig. 10;

Fig. 12 is'a sectiontaken substantially along the'line 12-42 in Fig. 10, showing one end connection of a counterbalancefor the rinsing head;

Fig. 13 is a graphieillustration of alight transmission curve for thdcolored or shaded areas ofia windshield havingthe dyed plastic interlayer'of the invention;

Fig. 14 is aplan'view of amodified form of rinsing apparatus;

Fig. 15' is a fragmentary, vertical, sectional view, taken substantiallyalongsthe'line ll 5 in Fig. 14; and

Fig. 16 isa-fragmentary, sectionalview-Jaken substantially along ,theiline'l 6-4 6 inFig. 15.

Referring now moreparticularly to the drawings, it will be noted that the automobile shown in Fig. 1 has-large-window areas, and that the. windshield It) extends upwardly to. ag-reater extent than heretofore andds bent so. as to actuallyform the forward roofportion of thecar. This type of design provides an extremelywide range of vision for the occupants'of the vehicle and opens up the field of. vision from the carior greater enjoyment of the driver and passengers at most hours of the day andrnightr One very important disadvantage of this design,.however, thoughit may be only occasional, is that rays of the sun,- .evenwhen at. averyisteep' angle, may pass throughthe windshield; Or, differently expressed, whenithe sun is on'lyslightly past its zenith, it. may... shine through a Wind'- 4 shield of this design when the car is traveling toward the sun. For that matter, similar difficulty is encountered, even with fiat glass Windshields, when set at the angle common to most present day automotive designs.

This is of course undesirable, because of the effect of the direct and reflected glare, from light shining on the windshield, on the eyes of the front seat occupants, and also because of the heat that is-brought into the car in this way.

Attempts have recently been made to overcome this difliculty byproviding opaque sun visors projecting outwardly over the windshield and at an angle thereto; and, in some cases, over the doors. However, while these effectively cut 01? the rays of thesun, they alsodefeat the primary purpose of the wide view Windshield design. In addition, they are open to all of'the objections to an extra accessory that juts out from the main body of the automobile, ruining streamlining and cutting down speed. (Actual tests shown that such visors will cut'downcar'speed'sasmuch'as 5to lOmiles perv hour.)

as to. suggest the use of prism reflectors incars "equippedwith them to overcome-this-serious disadvantage:

Now'we have found that this problem of. glare can be effectively solved-in an entirely difierent way, by "the provisionof an antiglare-meansthat forms an integral part of thelaminated'safety giassofth'ewindshield and will cut out the objectionable-rays without-materially affecting desiredvisibility through :the glass:

We'do' this primarily byg'overning, by gradation, the amount" of light permitted to enter throughagi'venarea of the windshield, thus giving light whereneededwitliouteblin'ding the occupants and; at thesame time, cutting out light neutral shading ll within thewindshield' itself,

and is vignetted or graduated in. shade from a deep hue at-I2 alongthe topmargin of the-winch shield; which maybe opaque',v or nearly opaque, to a very light hue l3 in thetrarea' adjacent the essential viewing area- M of the driverv and through which he sees theroad' and oncoming trafiic;

The advantageofr' this arrangement willbe. immediately apparent. Thus; the depth of. hue or color or shade, and 'consequentlythe glare-reducing properties, are greatest. in" the areav from which thegreatest glareiwillcome; and lightest the area where-thetgreat'est. visibility is required. In other words; the amount of. light reaching the eye'of: the driver. or: rider will. be gradually increased as I he Shift/$1118: line of sight downwardly toward the area where completev visibility is essential f and; conversely. the amount of light reaohing his eye will: be progressively decreased as he moves lineofsight upwardly towar'd'the-area of 'potentially, greatest glare;

A further advantage' is Ith'at" theobservers eyes areprot ected whilelookingfat bright, higher objectssuch. as the sky; mountains; andso' forth;

whereas-his visionis in no=way-obscured when looking atobjects on the road: or? on the ground, around or below the horizon level.

To illustrate this feature morepla'inly, there is shown in Fig. 1 3 a light transmission. curve for a Windshield made in accordance? with this- Moreover; overhead stop'lights and danger signalscan'n'ot be seen through them and manufacturers of thesevisors' havegone so far invention and wherein the distance from the top of the shield is plotted as the abscissa and the per cent of light transmission through the shield is plotted as the ordinate. From this curve it will be seen that as the driver lowers his eye from the top of the shield, designated A on the graph, to a point anywhere in the colored or shaded area, which in this case is inches wide, he can select any area of light transmission best suiting the particular driving conditions encountered. Should no glare be encountered, he can then view traflic through the uncolored area of very high and constant light transmission.

As best illustrated in Fig. 2, laminated safety glass of the type generally employed in automobile windshields is made up of two sheets of glass 55 and I6, and an interposed layer of a relatively soft but tough thermoplastic material l1, all bonded together under the action of heat and pressure into a composite unitary structure; and, as explained above, the antiglare portion of a laminated glass unit made according to the present invention is produced by coloring or giving a neutral shade to an area of the plastic interlayer [1 before laminating it together with the glass sheets.

Contrary to the opinion of leaders in the dye industry, we have discovered that we can satisfactorily accomplish this, and can even obtain a uniformly graduated and unstreaked vignetted effect where desired, by dyeing a marginal portion of the plastic interlayer sheeting. As a matter of fact, we believe that this is the only way the desired effect can be obtained in a commercially practicable and satisfactory structure.

The dyeing can be done by a number of different means, but in Figs. 3 to 12 of the drawings there is illustrated an apparatus that has proved very satisfactory for the purpose. As best shown in Fig. 3, this dyeing apparatus includes a framework I8 made up of a pair of longitudinally extending, horizontal channels I9 supported upon floor beams 23 and connected together by bridging members 2| extending transversely thereof between the upper ends of the floor beams.

The plastic sheets 22 are adapted to be carried into and through the dyeing apparatus upon a supporting carriage 23. The carriage 23 is rectangular in form being constructed of four angle irons 24, welded together in the form of a frame, and four upwardly extending angle irons or corner posts 25 bolted to the corners of the frame. Depending from the end angle irons of the carriage 23 are a series of adjustable hook bolts 26, arranged in regularly spaced. relation therealong, to support the plastic sheets to be dyed.

For ease in handling the plastic sheets 22 during the dyeing procedure, we prefer to mount them on suitable carrying and dipping frames 21. As best shown in Fig. 8, these frames may be of rectangular open shape, having top, bottom and side rails 28, 29, 3B and 3|, respectively, of light metal, with the top rail 23 being provided with end extensions 32 by which the frames can be suspended from the hook bolts 26 of the carriage 23.

The plastic sheets 22 can be secured to the frames 21 in any desired manner but we prefer to adhesively secure them in place by first coating the frame surfaces with a plastic solvent and then smoothing the marginal edges of the plastic sheet into full contact with the frame.

To start the dyeing procedure, a carriage 23 is supported at the loading station B upon rails 33 and 34, secured to the channels [9, and adapted to be engaged by grooved wheels 35, mounted on the outside of the posts 25. It will be noted that the rail 34 is in the form of an angle iron which presents a flat surface to engagement by the wheels. With this arrangement a slight sidewise sliding motion of the carriage is permitted during its longitudinal rolling movement from the loading section and into and through the subsequent rinsing sections. Also, the fact that all four of the wheels 35 are grooved permits the carriage to be properly located on the rails regardless of which end of the carriage is introduced into the loading section first.

With the carriage 23 located in the loading section B, a plurality of frames 21, to which plastic sheets have been attached, are hung on the carriage from the hook bolts 26. As soon as the carriage has been loaded it is ready to be moved into the dipping section C.

Within the dipping section C, the tracks 33 and 34 are cut out as shown at 36 in Fig. 5, and located in this cut-out area is a vertically movable dipping elevator 31 which includes a horizontal framework 38 made up of four channel irons. The framework 38 is supported for vertical dipping movement upon upwardly extending posts 40.

The opposite side members of the framework 38 carry rails 4| and 42 which are similar in form to the rails 33 and 34, respectively, but are located inwardly thereof to receive the grooved wheels 43 of the carriage 23 and which are mounted on the inside of the corner posts 25. Thus, as the loaded carriage 23 leaves the loading station B and moves into the dipping station C, the wheels 35 of the carriage leave rails 33 and 34 and the wheels 43 ride onto the rails 41 and 42 to locate the plastic sheet carrying carriage on the elevator 31. From this position, the lower margins of the plastic sheets can be immersed into a vat 44, which is supported on horizontal angles 45 extending between the floor beams 2!), and contains a supply of dyeing solution, as indicated at 46.

When the carriage is in position on the elevator framework 31, it is placed under control of a system which lowers the said framework a predetermined distance toward the bath, after which a timing device operates to cause the margins of the plastic sheets to be moved slowly downward in a manner to gradually and progressively immerse the area of the plastic sheets that it is desired to color or shade into the dye solution 46.

While various elevator systems may be advantageously and interchangeably employed for this purpose, i. e., hydraulic, electric or mechanical combinations, we have selected as a preferred construction, a lever arm type structure operated by a motion controlled cam and slide plate. As illustrated in Fig. 4, for example, a slide plate 41 is connected to the posts 40 through a linkage 48 which includes a compound rod 49 and pivotal arms 50 and 5|. The rod 49 comprises a pair of threaded rods 52 and 53, interjoined by a turnbuckle 54 by means of which the length between the extremities of the said rods may be altered to locate the rails 4| and 42 of the framework 38 substantially level with the rails 33 and 34. The rod 52 is threaded into a link 55 pivotally attached to the slide plate 41 by a pin 56 while to the outer end of the rod 53 a clevis 51 is threadably attached. The clevis 51 is drilled to receive pins 58 which are inserted through the ends of arms 50 and 5| and the adjoining sides of the clevis; The arms 50 and 5| are journaled, so as to revolve, in bearings 59 mounted on' columns 60 of the frame I8. More" particularly, the arms 50' and 5! each have a centrally disposed tubular portion 6 I. from which extendsbars 62, 63. andfi l, the-bar B2 of each arm' being related, at its outer end; tothe clevis 57 by the pin 58.

Asbest illustrated in Fig. 5, the bars 63 and 64 of each arm are interconnected. at their outer ends by a rod 65, the projecting ends of which are journaled in bearings 56 secured to; the upwardly extended. posts 40 of the framework 38. Thus, as the slide plate 41 moves upward-ly,the arms 59 and 5i will revolve on their respectivebearings 59' and tilt from the positions indicated inv phantom line (Fig. 4') to the position shown in full lines, in. which positionthe carriage 23" is at the lowest point ofv the dippingstroke; Down ward movement of theslideplate inversely produces upward motion of the framework or removal of theplastic sheets from: the dyeing solution 46 contained" within the vat M.

Movement of the slide plate, in. either direction, is: designed to efiect rapid',. partial descent of the carriage 23 and the plastic sheets-22, suspendedtherefrom, subsequent descent controlled by the surface of a cam. 61: and after'a predetermined time period, rapid elevation to quickly remove the said sheets. Accomplishment of these sequential phases of operation is achieved by the operation of geared? unit which are mechanically related to the slide plate d1. Thus, the geared unit 68' operates a linkage 69; comprising arms l and 71', the arm 70. being keyed to the shaft T2 of the unitfit and pivotally connected: to the arm H by a pin E3; The arm H is: slotted, as indicated at 74,110 permit free movement of a stud 15- therein upon movement of the stud by the slide plate 4"! in which said: stud is fixedly secured.

Motion of the slide plate is caused by the pull exerted by weight of the carriage 23:through the arms 50 and 51 and compound rod lfi; However, when the carriage 23" is received on the-framework 38, the efiect of such a weight force: is oilset by a resistance established in. the unit 68, the brake of its drive motor and the drive beltthereof; Operation. of the unit E58 thus creates a mechanical counter-balance. and: during av portion of'such operation afiords a control' for-descent of the framework 38 and carriage. 23*. arm is of the linkage 69 hascompleted' substantially a half revolution, the slide plate is raised sufficiently to place itin the control surface area of the cam 61. The cam is engaged by a roller 16 carried by the plate Tl" near its lower end by a stud 11.

Through electrical controls (not shown) the unit 68' is new rendered inoperative and a similar gear drive, indicated at T8, is started. The'cam- 5-"! is secured toa face plate 79 keyed to the output shaft of the unit 18 and the influence afforded during its rotation is determined by the cam areas of its surface. The roller Tiithus' rides on the cam surface which gradually permits rising of the slide platewithin slide or guideways Bil: secured tothe main structure l8. The timing. cycle of the dipping produces the graded area of the plastic sheets and consequently variously generated cam When the sheets may be established and when this point is reached, it is desirable to rapidly raise the. carriage. Adequately positioned controls are now effected to resume operation ofv theunit 68k and, through the linkage 6'8; to-engage the stud 75 by an end of theslot Hi in; the. arm ll. Rotation oi? the shaft '12 to complete a. full revolution of the arm 19. of said linkage 65 produces consequent separation of: the roller 16 from the surface of the cam 5:7 and delivery of. the slide plate t7 tothe lower extremity of its travel- Through the rod 29 and arms 50 and 5 i:, this movement of the plate 4? is transmitted to the framework 38 to raise it and the carriage 23 30 a point where the rails H- and 82' on the elevator framework are again in alignment with the rails 33- and 34 of the loadin and rinsing sections.

Immediately upon completion of the dyeing cycle, the carriage 2 3 is propelled toward the rinsing sections D and E and, as it moves out of the clipping section (.7, the wheels, is ride off the rails 41 and 52 on the elevator while the wheels 35 ride onto the section of the rails 33-. and 3 5" leading to the rinsing sections. The manner n which the wheels 43 leave the rails ll and: M While the wheels 35 engage the rails 33' and 34 is best shown in Fig. 5.

As the plastic sheets on the carriage 23' move into the'first rinse section D, they are immediately subjected to an alcohol rinse by means of spr y pipes 31. The pipes 81 are arranged in pairs along a manifold pipe 82 and their ends are suitably flattened and bent, as at 8-3, to direct the alcohol against the opposed surfaces of adjacent sheets. Preferably, the-spray pipes 8| are of sufiicient height to present the-alcohol in areas along and above the areas of the plastic sheets which have been attested by the dyeing solution. shown in Fig. 9, the manifold pipe 32 is supported in carriages 84 which traverse rails 85 and 5; horizontally disposed along and above the sides of a receiving tank 81. The tank or tray 8! is supported on the angles 45' and is connected to a usual sump by the pipe 89.

lFhe carriages 8 3 are supported by wheels Qt on the rails 85' and 86 and are propelled by chain belts 9|, driven by a crank 92 and trained over sprocket gears 33 and 94. The sprocket gear 93',

constituting the driver for the belts 9|, is keyed;

to a shaft 55 journaled in bearings Qfiand extend.- ing through the rails 35 and ES. Ordinarily, one pass of the pipes 8| will produce the-desired rinsing effect on the plastic sheets and the dyed areas thereof; however, if further rinsing is found; necessary, rotation of the crank 92 in the oppositedirection will return the carriages to-a position substantially as shown in Fig; 3.

The alcohol is delivered to the manifold pipe 82 from a supply pipe 97, through a length of flexible tubing Qeand suitable fittings as.

The rinsing apparatus just described has been found to be very satisfactory in rinsing relatively short sheets of plastic such as those to be used in half Windshields. However, for longer plastic sheets, such as are used in, one-piece Windshields, it is preferred to employ a modified form of operating mechanism for'the rinse pipes 8 4.

Thus, it has been found that it is advantageous to rinse the dyed sheet by spraying the dyed area on each side of the; sheet with a single moving stream of rinsing liquid, as already described, in order to avoid streaking. However, it is also essential tov rinse the dyed area, and especially that portion of the: dyed area that is adjacent the fade-off line, as quickly as possible, to insure a v 201. opposite directions, the cable 206 is trained back fand' 'fo'rth over a series of pulleys 208 mounted fat Opposite ends of the rails 203. Y

9 minimum exposure of the plastic along this line to the dye in order to achieve an almost imperceptible cut-off line between the dyed and undy d areas.

This is satisfactorily accomplished on relatively short sheets by the rinsing mechanism described above because, as pointed out there, the sp y pipes 8| go into operation as soon as the sheets are moved into the rinse section D, and can be quickly moved from one end to the other of the sheets. In the case of longer sheets, however, the time required for the pipes 8| to move from one end of the sheets to the other results in the dyed area at one end of the sheet being exposed to the dye for a sufficiently longer time, prior to rinsin end of the sheet that is last to be rinsed; but it also results in a quite perceptible cut-off line toward the end that is last to be rinsed.

Now we have discovered that these difficulties to give a noticeable increase in the shade of the can be overcome, without losing the advantage of the single moving rinse spray at each side of the dyed sheet, by a modified form of operating mechanism for the spray pipes 8I which causes the pipe praying one side of each sheet to move from one end to the opposite end of the sheetwhile the pipe spraying the other side of the sheet is moving in the opposite direction and from said opposite end to the first end of the sheet.

In this way, any variation in shade in the dyed area on one side of the sheet from one end of the sheet to the other will be compensated 'for. .by a similar variation in shade in the opposite direction in the dyed area on the other side of the sheet. Similarly a darker fade-off line on one side at one end of the sheet will be compensated for by a lighter fade-off line on the other side of the same end.

One form of operating mechanism adapted to accomplish this result is shown in Figs. 14 to 16.

As best shown in Figs. 15 and 16 the pipes 8I the rinsing section D. To this end each of the.

carriages 200 are provided with two pairs of "flanged wheels 20l and 202 which embrace, and

are adapted to run along, a rail 203' mounted below and in alignment with the space between eriage is stopped, the head IOI is moved downsheets 22' when they are movedinto the rinsing,

section D.

The carriages 200 also carry headers 204 which communicate with the pipes 8 I that are mounted .thereon, and which headers are connected ,toxa

suitable fluid supply manifold (not shown). by,

flexible pipes 205.

movement in unison by suitable clips or the like,

In order to move alternate carriages in The carriages 200 are propelled by means 01' a chain belt 9|, trained over sprocket gears 93' and 94 and driven by a crank 92 which is mounted on the shaft 95 for the sprocket gear 93'. To this end one of the outside carriages 200 is connected to the chain belt 9 I as at 209 so that I upon turning of the crank 92' in a counterclockwise direction the connected carriage 200 will be moved from one end of the adjacent plastic sheet 22' to the other. At the same time, by reason of the connecting cable, all of the carriages 200 that are at the same end of the sheets to be I rinsed will move in the same direction, while the carriages that are at the opposite ends will move in the opposite direction.

From the first rinse area D, the carriage 23 is propelled along the rails 33 and 34 until it and the suspended plastic sheets 22 are positioned above the tank or tray I00 of the second rinsing area E. The arrangement of the tanks 81 and I00, as seen in Fig. 9, prevents dripping of the -escaping rinse as the carriage is moved from one rinse area to the adjoining area. Preferably, in the second rinsing area for the plastic sheets provision is made for rinsing said sheets with water -and subsequently with distilled water or condensate.

According to the desired arrangement of water rinsing, the distilled water is pumped into a pipe supplying system in a manner that either can be independently directed to the head IOI.

This head, as shown in Figs. 9 and 10 and indicated by the numeral IOI, comprises a plurality of horizontally'disposed pipes I02 having spray orifices I03 drilled therein. Preferably, the orifices are located diametrically opposite in the wall of each of the pipes with the exception of the outermost pipe at each side. Necessarily, the orifices of these pipes are provided in one. wall only. The pipes I02 are connected as by welding to a manifold pipe I04 which in turn is welded 'toia vertically extending pipe I05. The pipe or standard I05 jointly serves as a conduit and as 1a slide. member by which the head IOI generally is raised or lowered with reference to the tank I Hill, the frame I8 of the apparatus, or the plastic sheets 22.

As illustrated in Figs. 6 and 10, the pipes I02 are arranged to direct the water rinse toward opposed surfaces of the adjoining sheets in areas well above the dye area to create a uniform floodingof the sheets as the water descends on the surfaces. The head IOI is also designed so that the maximum height of the pipes I02 may be adjusted according to the width of the dyed area. In ordinary operation, the height of the pipes, as shown in Fig. 9, has been found to be satisfacztory for. starting the second rinsing as the carriage is propelled to deliver the plastic sheets between the plurality of spray pipes I02. Once the carwardly so that the rinsing effect of the water "continues until the pipes I02 are carried well beneath the frames 27. I

The head I0! moves vertically through a path established by a block or collar 1 06 through which :the pipe I05 passes. The collar is supported 'within' and forms a part of the bracket I01 secured to the apparatus frame structure. Beneath the bracket I01, the pipe I05 is clamped between blocks I08 and I09, each of said blocks having inner surfaces contoured to receive the pipe. To securely clamp said pipe, bolts IIO are extended through the block I08 and threaded into the block 109 which is fixedly secured to the angle III 11 comprising in part a traversing carriage II: for the head Ill-I. The angle III extends transversely of the frame structure I8 and substantially along the outer surfaces of the legs H3 thereof.

Blocks I I4 are secured at the ends of the angle III;: said blocks having angularly formed surfaces H5 which cooperate with surfaces H6 of latches II'I. When the carriage is raised, and near the top of its movement to position the pipes I02 as shown in Fig. 10, the cooperating surfaces H5 and H6 produce deflection of the latches II'I until the lower surfaces of the blocks H4 can be engaged by the latches H! to retain the head IOI generally in its elevated position. The latches are carried by a cross shaft H8 journaledin the legs I I3 and are urged in one direction to; engage the blocks I I4 by a spring H9 extended between one of said latches and a plate I20 attached to the adjacent leg H3.

If desired, a handle I2I may be affixed to the block I98 in order that the carriage can be manipulated manually in either direction during the rinsing operation. Also, to balance. the carriage and assure its descent with an evenness of movement, a weight I22 is connected to the carriage by cables I23 which are trained over pairs of pulleys I24 and I25. One means of attachin the cables to the carriage is shown in detail in Fig. 12 wherein will be seen a bracket I26 secured to angle III, said bracket having suitable clamping blocks I2! for grippin one end of the cable.

The pairs of pulleys I24 and I25 are arranged beneath the tank I00, as shown in Fig. 9, and pivotally supported on brackets I28 attached to the angles 45 of the framing structure l3. As shown therein, each of the cables. is trained over a pulley IM to the pulley I25 and downwardly toclamps I29 forming a part of the weight. I22.

When the head IIII is to be lowered, either of the latches H1 is engaged by itsprojectinghandle to release the blocks 1 I4 and accordingly the carriage H2. During the descending movement of the head ml, the spray of water from the pipes I02 will be directed against the surfaces or the sheets 22 and in running therefrom will be gathered in the tank I and discharged to a suitable drain through the pipe I30.

previously indicated, it has been found advantageous to rinse the plastic sheets with ordinary city main water and subsequently with distilled water or condensate. Such an arrangement is conveniently shown in 3, wherein the'distilled water is supplied from the pipe 13I while pipe I32 supplies ordinary main water, each of said pipes having suitable valves for governing the rate of flow. The supply pipe I3I extends to a reservoir tank I33 which is connected by a pipe I34 to a motor operated pump I 35. The pump outlet is connected by: a conduit I38 to a fitting located in the pipe I32. .extending end of said pipe I32 is then connected to the vertical pipe I of the head IN by usual fittings I3"! and a flexible section of hose l38;

Thus, when first rinsing the sheets .22, the pump I35 is inoperative and city water through pipe I32 is supplied to the head III I by thezhose I38. Following this rinsing, the valve in the pipe "132 is closed and the head raised to its original upper position. The pump 435 is then started and distilled water will be withdrawn from the reservoir 133 by the pipe I34, the pump, and

through the conduit I 36 to the flexible hose section I38 so that as the head IIII is subsequently lowered, distilled water, or condensate, will be directedagainst the plastic sheets in a. final rinsing operation.

Upon completion of the second rinsing operation, the frames 2' I and attached sheets-ofplastic. 22 are removed from the hook bolts 25 and removed to a drying area. When the carriage 23 is emptied of frames, it can be removed to the loading station. B of the apparatus and the spray head III-I returned to its elevated position for subsequent use.

In employing the apparatus just described to practice our invention, we first fill the vat 44 witha suitable dye solution. We prefer to employ dyes of a .color or shade that are soft and pleasing to the eye, that permit objects to be observed through them with a minimum of distortion to their appearance, and through which primary colors such as the red, green and amber of trafiic lights are readily distinguishable.

There are a number of dyes that have such desirable characteristics, but we prefer dyes that also have recognized better than average light stability, and stability to heat at the temperatures. required to bond glass and plastic interlayers together.

Examples of such dyes are:

The sodium salt of 1:4 bis ortho-sulpho-paratolyl ammoanthraquinone; (Color Index No. 10.7.8). sometimes known in the trade as Alizarin Cyanone Green G ,E'x the-sodium salt of monosulpho. 1:4 bis paraetolyl. am-inoanthraquinone, comm-only called Alizarin Cyanone Green GN"; duPont Orange L con o. (color Index No. 151); duPont Chmmacyl Black -W; Alizarin Fast Blue RB; Alizarin Violet NRR; Acetamine Black CBS; and duRont Nigrosine Base (color Index No. 364).

After selection of; the dye, it is necessary to make up the dye solution. As illustrative of our procedure, in using the sodium salt of 1:4 bis ortho-sulphoeparaetolyl aminoanthraquinone, hereinafter referred to as Alizarin Cyanone Green G. Ex dye, we prepare a dye solution by dissolving about 2% Cf-this dye in a by volume mixture of aqueous denatured alcohol. While solution can be accomplished in many ways, one. method to prepare the solution by heating 400 grams of the dye to reflux temperature 1 0 liters of Formula I denatured alcohol ethanol+-,-5% methanol) with stirrin .diluting with 10 liters of distilled water and then filtering,

Othen solvents, for. the dye, such as water, methanol water mixture, isopropanol water mixtures, etc, may be.satisfactorily.employed. The main object is to bring dye into solution using mixtures which will not too rapidlyattack the plasticto be dyed during the time and temperature cycle to be used.

When. the. vat-44; has been filled with the desired dye solution, a group of plastic sheets cut to the required-size are fixed to the frame 21. These plastic sheetsare preferably out oversize to :permit attachment to the frames and to allow .:-for.subsequent orientation when assembling the dyed plastic with the glass sheets. A carriage 23, positioned within the loading section B, is thenhnng with a capacity loadof framesil to whichpthe plasticsheets "to besdyed havebeen aflixed.-' Thepfulilicarriage is. then movedv from 13 resin sheeting plasticized with 41 parts dibutyl Cellosolve adipate, now used by the assignee company, or when plasticized with other suitable plasticizers such as dibutyl sebacate, triethylene glycol dihexoate (commonly called B-Gh) or a mixture of triethylene glycol caprate and triethylene glycol caprylate (known to the art as J-24).

As explained above, by employing a cam of the proper shape, and by proper control of its driven of the sheet is immediately rinsed with a mixture of 50% denatured ethanol (95% ethanol-% speed, the plastic sheets can be immersed in the dye solution 46 in a manner to produce an even shade over the entire area to be dyed. Or, the margin of the plastic sheets may be shaded gradually and uniformly from a deep hue at the edge to color extinction at the fade-off point. Or, the desired vignetted effect can be obtained by a series of bands with adjacent bands being of graduated intensity from a deep hued band at the plastic edge to a graduated light hued band merging into nothingness at the fade-out or cutoff point.

The advantage of the latter arrangement is that it may be desirable to provide relatively wide areas of substantially uniform hue in certain parts of the colored or shaded area. For example, in a windshield which is bent upwardly over the heads of the front seat occupants, it may be advisable to have a relatively wide band of the darkest hue in that part that is exposed to the direct rays of the sun from overhead.

In order to set the controls to obtain these desired results, it is necessary that a definite schedule for graduated immersion of the plastic in the dye solution be established, and this schedule will depend on the particular shaded effect to be produced.

In immersing the plastic in the dye, it is best to move the elevator 31, carrying the carriage 23,

rapidly downward to a predetermined indexing point, at which point the lower edges of the frames 27 are in the dye and the main body of the plastic is about to be immersed. From this point on, any immersion schedule which will give the desired vignetted effect can be used.

For example, by dyeing plastic sheets in ac-- cordance with the following immersion schedule, using the Alizarin Cyanone Green G Ex dye solution described above, and then laminating them as interlayers between two sheets of special glass to be hereinafter described, finished Windshields having the transmission curve shown in Fig. 14:, will be produced.

Immersion schedule I Upon completion of the dipping cycle, according to the desired immersion schedule, the elevator 31 is raised to withdraw the plastic sheets from the dyeing bath as rapidly as possible and the carriage 23 is then quickly moved, first into the first rinsing section D where the dyed portion solvent and/or water removal.

Two of the steps of our dyeing procedure which are of special importance in producing an accurately controlled intensity in the colored or shaded area of the dyed plastic and in maintaining the area free of streaks and other irregular color variations are: (1) the particular dipping procedure that we use, and (2) the special rinsing technique.

Thus, .it will be noted that We do not dip the plastic by first immersing the entire area to be colored and then slowly withdrawing it from the bath, but that, instead, we immerse the area to be shaded slowly and progressively into the dyeing bath until the desired area has been immersed and then quickly withdraw the plastic from the bath. This reducesto a minimum the time during which the free dye solution on the plastic can run down over the dyed area.

This also permits the removal of all parts of the dyed area from the bath just as soon as they have been in contact with the dye solution for the required length of time. And we rinse the dyed area immediately after it has been removed from the bath.

We have found that the composition of the rinse used after the dye bath will depend upon the solvent composition of the dye bath, but that in general mixtures of various water-soluble alcohol-water mixtures are most suitable for producing an imperceptible fade-o-fi from the dyed to the undyed areas.

This is rather surprising because actually the dyes we have used are more soluble in water than in alcohol, Nevertheless, when the dyed area is rinsed first with water, a sharp cut-off line results after drying. On the other hand, when the dyed area is rinsed with alcohol first, the cut-off is much less perceptible and the dyed area blends much more smoothly into the undyed area.

After rinsing, the dyed plastic must be dried. This is most important since considerable quantities of solvents from the dye bath (even up to 25% of the weight of the dipped area of the sheet) may be absorbed during the dyeing process. Actually, all of these solvents and/or water must be removed before the laminating step since not more than .5% can remain if satisfactory adhesion and heat stability (failure to bubble in service) is to be attained.

The plastic therefore is dried on the frame, preferably in an oven at 155 F. to accomplish Other means, such as by leaching in non-solvents for'the plastic which are solvents for th dye bath constituents, may be employed as a preliminary step to oven drying. We have found that it is desirable in some cases to preliminarily dry the plastic for a short time, until tack free, in a clean, dirt and dust free oven, and then finish drying after dusting the surface with a salt such as finely divided sodium bicarbonate. This insures that dirt fall- :15 completed unit will have much greater light stability, and better 'antigla're properties if a protective type ofxglassis-used with the dyedplastics. There are a number of glasses of this general type that will give satisfactory results, the most important properties required being that they transmit a relatively high percentage of visible light while, at the same time, .cuting off a relatively high :percent of the ultra-violet light.

Although our glare-reducing unit is 1 especially valuable for use in glazing automobiles, .aircraft and similar vehicles, it will be appreciated that it has many other potential uses as well; and-in lieu of laminating the shaded or colored plastic wtih two sheets of protective glass, we may also laminate it withasingle layer of suchglass. Or, it may be incorporated into a unit including more than two sheets of glass and more than one plastic interlayer and/orrin somecases, with an air space between adjacentglass sheets.

In fact, it is to be understood that the iorm of the invention herewith shown and described is to be taken as a. preferred embodiment of the same, but that various changes in the-shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope'of the-subjoined-claims.

We'claim:

1. In apparatusfor dyeing predetermined areas of plastic sheets prior to laminating them with sheets ofglass to form'antiglare screens, a container 'for a bath of dye solution, a carriage for supporting aplurality'of plastic sheets above said bath, means for creating relative movement between said container and'said carriage to first immerse said sheets in said bath and tothen remove them therefrom, control-means-associated with said'rneans for creating relative movement for causing said sheets to be moved relatively slowly into said bath at varying speeds for a predetermined distanceand to be then removed at a relatively high constant speed from said bath, horizontally movable spray -means positioned in proximity to said bath for directing one type of rinsing medium onto the dyed-areas of each of saidsheets immediately after removal thereof iromsaid dye bath, and additional spray means positioned in proximity to said firstmentioned spray means for directing another typeof rinsing medium onto the dyed and rinsed areas of each said sheets.

.2. In apparatus fordyeingpredetermined areas of plastic sheets prior to laminating them with sheets of :glass to form antiglare screens, econtalner for a bath of dye solution, a carriage for supporting a plurality of plastic sheets above said bath, means for creating relative movement between said container and said carriage to first immerse said sheets in said bath and to then remove them therefrom, control means associated withsaid means for creating relative movement for causing said sheets to be moved relatively slowly into said bath at varying speeds for a predetermined distance and to -'be then removed at a relatively high constant speed from said bath; and spray means comprisinga'horizontally arranged pipe horizontally molvable in 'a path parallel to the plane of said sheets, 'a plurality of pairs of vertical, pipes extending upward from said horizontal pipe'a'nd'positioned'to'lie between fig and at eitherside of said sheets, nozzle portions on each of said vertical pipes with said nozzle portions on the two pipes of :each pair being pointed in approximately opposite-directions,

means for moving said horizontal pipe, and'means for supplying a rinsing medium thereto whereby said medium will be directed onto the dyed areas ,sofeachof said sheets immediately after removal thereof from said dye bath,

3. In apparatus fordyeingpredetermined areas of plastic sheets prior to laminating them with sheets of glass to form antiglare screens, a container fora bath of dye solution, a carriage for supporting plurality of plastic sheets above said bath, means for creating relative movement between said container and said carriage to first immerse said sheets in said bath and to then remove them therefrom, control means associated with said means for crea ting relative movement for causing saidsheets to be moved relatively slowly into said bath at varying speeds "for apredetermined distance and to be then removed at relatively high constant speed from said bath;

and spray means for directing a rinsing medium onto the dyed areas of each of said sheets immediately after removal thereof from said dye bath comprising opposed nozzles positioned to receive a dyed sheet 'therebetween, means for -moving said nozzles alongpa ths parallel with the plane .of said sheet, and means for supplying a rinsingmedium to said nozzles.

4. In apparatus for dyeing predetermined areas of plastic sheets prior to laminating them with sheets of glass to form antiglare screens, a container for a bath of dyesolution, a carriage for supporting a plurality of plastic sheets above said bath, means for creating relative movement between said container and said carriage to first immerse said sheets in said bath and to then remove them thereirom,-control means associated with said means 'for creating relative movement for causing said sheets to 'be moved relatively slowly into said bath at varying speeds for a predetermined distance and tobe then removed at a relatively high constant speed from said bath; and spray means for directing a rinsing medium onto the dyed areas of each of said sheets immediately after removal thereof from said dye bath comprising opposed nozzles positioned to receivea dyed sheet therebe'twee'n with one of said opposed nozzles-being on one side and adjacent one end of said sheet and the other nozzle being at the opposite side and adjacent the opposite end of said sheet, means for moving said nozzles in opposite directions along paths parallel with "the plane .of said sheet, and means 'for supplying a rinsing medium to said nozzles.

JOSEPH D. RYAN. PAUL T. MATTIMOE.

References Cited in the -file of this patent UNITED STATES PATEN'I S Number Name Date 682,412 Hunt -1 Sept. 10, 1901 1,564,615 Olsen no Dec. 8, 1925 1,877 ,81'1' Cool; Sept. 20, 1932 2,381,183 Richards Aug. 7, 1945 2,593,405 Beckman Apr. 22, 1952 

